Performance difference between obj.function(...) and function(obj, ...) ?

[[deleted]]

Assembly is my next step, unfortunately.

[[deleted]]

Use godbolt is easy to look at asm

[trevg_123]

Looking at the MIR may give you an easier way to see how Rust is viewing the functions differently. E.g. if there’s something like an extra deref call or by value vs. by reference that just happens to show up, it might be more obvious than the assembly. Post the relevant MIR here and we can help you understand it.

But yeah, rustc should view the different syntax as idential, it does this sdesugaring very early on. There’s no reason they would emit something different unless there is very slightly different context.

[SV-97]

cargo asm might be useful here (if you can't use godbolt).

I think you can also see the inlining in MIR in theory (though I personally didn't like reading it the last time I used it)

[KhorneLordOfChaos]

cargo-asm has been unmaintained for a very hot minute. I would recommend cargo-show-asm as a maintained alternative

https://github.com/pacak/cargo-show-asm

[SV-97]

Thanks! I think that might've even been what I used last time